I have created a script in selenium in odoo framework in python , now I want to test it for load testing then which tool is best ?
should I have to make another script for load testing again or I can use the same script for a load testing , if yes then how can I use it
you cannot do performance testing with Selenium. you can use Jmeter or any other Performance/Load testing tool
You can combine your selenium script with JMeter webdriver and then perform a load test.
Taurus automation framework (it's free, open source and written in Python by the way) has support of Python Selenium tests so you should be able to run them in multithreaded manner.